Hi, i was just wondering if anybody could guide me on how i should do this question.

The height of the roof at any point is given by the function z=x^2/8-y^2/16. Find surface area membrane required for the section of the roof shown contained in the circular region x^2+y^2<36.

I started the question by putting the z function into a parameter and finding the derivatives with respect to my two parameters u and v. Then, i took the cross product of Ru and Rv to find my normal vector. After, i took the magnitude of this normal vector but i don't really know what to do next.

Thank you